[malloc][RFC/Discussion] Handle endianness / Add endianness flag

[Bnaya]

following discussion on discord,
https://discordapp.com/channels/445761008837984256/445761258696736790/657739072470646794

TypedArray endianness is platform specific

Malloc supports loading external arraybuffers, that possibly was created & used on a device with different endianness.
For example: passing arraybuffer as binary data from server to client.

None Goal:
Fix the whole endianness issue for userspace values.

Possible things to do about it:

• Nothing: almost everything is LE

• Add a header flag, that is readable in an endianness-agnostic way to tell on which endianness the pool's arraybuffer was created on. so we can make sanity check and bail.

• Add static function on the lib to sniff the endianness on a given arraybuffer, to use before passing to a new instance of pool

• let malloc sniff it when providing existing arraybuffer and fail/transform the arraybuffer to the appropriate endianness.

[postspectacular]

@Bnaya haven't done anything specific on this yet, but just wanted to record a mental note here that the thi.ng/binary package now includes a IS_LE constant which will be true if the runtime env is little endian...

[Bnaya]

Cool!